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  1.     #include <iostream>
  2.     #include <vector>
  3.     #include <utility>
  4.  
  5.     int main() {
  6.         std::vector<std::pair<int, float>> v = { {1, 1.5f} };
  7.  
  8.         // The interesting line:
  9.         const std::pair<int, int>& x = v[0];
  10.  
  11. 	    const auto& y = v[0];
  12.  
  13.         std::cout << "before:\n";
  14.         std::cout << "\tv[0]: " << std::get<1>(v[0]) << "\n";
  15.         std::cout << "\tx:    " << std::get<1>(x) << "\n";
  16.         std::cout << "\ty:    " << std::get<1>(y) << "\n";
  17.  
  18.         std::get<1>(v[0]) = 3.5f;
  19.  
  20.         std::cout << "\nafter:\n";
  21.         std::cout << "\tv[0]: " << std::get<1>(v[0]) << "\n";
  22.         std::cout << "\tx:    " << std::get<1>(x) << "\n";
  23.         std::cout << "\ty:    " << std::get<1>(y) << "\n";
  24.     }
Success #stdin #stdout 0s 3428KB
comments (?)
stdin 
Standard input is empty
stdout 
before:
	v[0]: 1.5
	x:    1
	y:    1.5

after:
	v[0]: 3.5
	x:    1
	y:    3.5
https://ideone.com/5jyiwD
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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